PowerPoint 4: Plumbing Fixings and Screws

PowerPoint 4: Fixings and Components in Plumbing

• Fixings and components used in common plumbing processes are the focus of this presentation.
• Learners will identify fixings, clips, clipping distances, surfaces, buried cable, buried pipework, and different fixing methods for various surfaces.
• Measurements of clipping distances and surface identification are also important learning outcomes.
• Performance of fixings on different surfaces is also a focus.

Screw Styles

• Various screw types exist for different applications, including countersunk, cross-head, Pozi drive, raised countersunk, round head, mirror, coach, and chipboard.
• Different screw styles include countersunk (flat), double countersunk, countersunk (oval), raised, round head, and domed.
• Countersunk screws sit flush with the surface, while others do not.

Types of Screws

• Different screw styles are classified based on their head shapes.
• Examples include full-bearing, washer-faced, double-chamfered, square, slotted-hexagon, countersunk, raised-countersunk, round, pan, cheese, raised-cheese (fillister), mushroom (truss), hi-torque, Phillips countersunk, Phillips raised countersunk, Phillips round-pan, Phillips round, countersunk button, hexagon socket, flat or cap hexagon socket, and knurled head.

Common Head Types

• Flat blade screws are used with slotted screws, and care should be taken to ensure the correct blade size for the screw slot.
• Phillips screws were originally designed in the 1930s to prevent over-tightening.
• Pozidriv screws are similar to Phillips screws but with an eight-pointed star shape for a better grip. They are not compatible with Phillips screws.
• Star head screws are used in specialized installations and appliances. Also known as Torx screwdrivers.
• Hexagon head screws (Allen keys) are commonly used in the gas industry for appliance servicing and installation.

Materials for Screws

• Brass screws are resistant to corrosion and suitable for high moisture areas. They are expensive but have a long lifespan. Concealed use, such as in bathrooms, is also an appropriate application for brass.
• Stainless steel screws, like brass, are very resistant to corrosion; this makes them suitable for high moisture areas, inside or outside use, and commercial applications. Expensive and long-lasting.
• Steel screws are a general-purpose type suitable for dry conditions, generally for interior use. Relatively cheap and durable.
• Chrome screws provide a decorative finish and are expensive and long-lasting. Used in exposed areas, including bathrooms.
• Zinc screws are general-purpose for interior and exterior use; they are also resistant to corrosion, cheap, and durable.
• Sheradised screws have limited outdoor use only.

Plasterboard Fixings

• Expanding plastic wall plugs and expanding metal cavity fixings are common choices.
• Spring toggle fixings are another plasterboard fastening system.
• Self-cutting fixings (self-tapping screws for metal) are also used for plasterboard.

Masonry Fixings

• Rawl bolts, self-tapping wall bolts, Fischer bolt basin sets, and standard plastic wall plugs are common masonry fixings.

Screw, Drill, and Plug Sizes

• Screw sizes (gauge) relate to drill sizes (mm) and matching plug colours for proper installation.

Pipe Clipping Distances

• Clipping distances vary based on the pipe material (copper, LCS, plastic pressure pipe). Specific distances are listed for 15mm, 22mm, and 28mm pipes.
• Horizontal clipping spacing and vertical clipping spacing are provided, depending on the pipe material.

Clipping Distances for Soil and Waste

• Specifications for horizontal and vertical clipping distances for soil and waste pipes are listed.

Clip Compatibility with Different Surfaces

• Compatibility of various clips with different surfaces (copper, LCS, Plastic PP).

Reasons for Clipping Distances

• Pipe support
• Limiting pipe sagging (especially when heated).
• Plastic pipes sag more than other pipe materials when heated.
• Smaller pipe diameters being weaker
• Vertical and horizontal forces also differ.

Surfaces in Building Fabric

• The presentation includes images of surfaces such as brickwork, blockwork, studwork, plasterboard, wood, and tiling.

Study Questions

• List 5 different screw styles
• List 5 different screw head styles.
• Describe the purpose of a mirror screw.
• List some plasterboard fixings.
• List some masonry fixings.
• Explain why the correct clip spacing is crucial.
• Give examples of different types of clips.
• State the clipping distance for vertical 15mm copper piping.